Treating hydrocarbon fluids



I molecular weight hydrocarbons.

' are encountered in the Patented Dec. 22, 1942 2,305,635 manure nrnnocannou FLUIDS Francis Owen Rice, Silver Spring, MIL, and

Winston D. Walters, Rochester, N. by mesne assignments, to Irocess Inc., Wilmington, Del., a corpora- Company, tion of Delaware No Drawing. Application October Y., assignors, Management Serial No. 362,871

. I 9Claims. .(cl. 260-683) This invention relates to the treatment 01' ydrocarbon fluids.

According to our invention, higher molecular Weight hydrocarbons are converted to lower Thermal proc-v esses for eflecting this conversion are known but we have found that by using a relatively small amount of a promoter, the rate of conversion is increased and the conversion may be carried out at lower temperatures. In our process the promotor which is used is diacetyl. Our invention may be used for the conversion of normally gaseous hydrocarbons to unsaturated hydrocarbons and for the conversion of mixtures of hydrocarbons containing normally gaseous paraflin hydrocarbons.

' with about .10%

The proportion of the diacetyl used as a promoter may vary between about 045% by volume to about 1.5% by volum of the hydrocarbon to be converted. amount of promoter, being greater for larger percentages of promoter. The rate of conversion increases with increases in the temperature and pressure, and with higher temperatures: and pressures shorter times of contactmay be used. The highest temperatures for the conversionsof saturated hydrocarbons promoted with'diacetyl promoted conversions of ethane. The catalytic effect of the diacetyl de creases gradually with time.

The normally gaseous paraflln hydrocarbons such as ethane, propane and butane require high temperatures for decomposition when no catalyst or promoter is used and at. such high temperatures the reaction is difilcult to control. We

The conversion-varies with the present. Thedia cetyl acts as a promoter to increase the rate of conversion. Pressures higher than those given in the examples may be used. another example, butane was decomposed under the conditions given in the preceding example except that only about 0.12,% of diacetyl by volume was used. About 24% of the butane was decomposed and the reaction products contained unsaturated hydrocarbons.

At lower temperatures-the rate of decomposition of the butane is decreased. For example, of diacetyl by volume and at a temperature of about 954 F., about 13% of the butane was decomposed after about-five minutes and the reaction products contained unsaturated hydrocarbons. I To convert propane into unsaturated hydrocarbons, about 1.0% of diacetyl by volume was added to propane and the mixture was heated to about 930 F. and under a pressure of about atmospherlc. About 5% of the propane was decomposed and the reaction Pylene and ethylene. The propane was maintained under these conditions for about 15-20 have found that if the conversion is carried out in the presence of a relatively small amount of diacetyl, the reaction takes place at a lower temperature to give increased yields and at such a lower temperature the conversion is more easily controlled.

For example, butane was heated under a pressure of about /2 an atmosphere to about 990 F. in the presence of about 1.0% of diacetyl by vol-' ume. After about five minutes under these conditions, about 32% of the butane was decomposed and the conversion products contained unsatu- ,rated hydrocarbons including butylene and ethylarated in any suitable manner. and furthertreated as desired. In all the examples using diacetyl as a promoter it is necessary to have the satu- 'ene. The unsaturated hydrocarbons may be Seprated hydrocarbon at a temperature such that.

the paraflin hydrocarbon would be itself decomposing at a measurable rate, if no promoter were seconds.

By heating the propane in the presence of about 1.0% diacetyl by volume to about 1112 F., about 20% 0f th propane was decomposed and the reaction products contained unsaturated bons. Increasing the temperature to about 1l57 F. and with the rest of the conditions the same, about 35 of the propane was decomposed in the presence 01' 1.0% diacetyl. '1 he reaction products contained unsaturated hydrocarbons.

In all of the above examples, the converted products may be treated to separate unsaturated hydrocarbons and the unconverted parafiin hydrocarbons' maybe recycled for further treatment in the presence of added diacetyl.

While we have given several examples of our invention, these are merely for the purpose of illustration and we are not as the proportions of the promotor, the temperatures and pressures and times of heating may be variedwithout departing from the spirit of our invention.

We claim:

1. A method of converting nonmally gaseous paraflin hydrocarbons to unsaturated hydrocarbons which comprises heating a normally gaseous paraflin hydrocarbon to a conversion temperature in the presence of a relatively small amount of diacetyl to convert the normally gaseous parafiln hydrocarbon to unsaturated hydrocarbons.

2. A method of converting normally gaseous products contained prohydrocarto be restricted thereto- 2 paramn hydrocarbons to unsaturated hydrocarbons which comprises heating a normally gaseous paraflin hydrocarbon to a conversion temperature in the presence of between about .045% and 1.5%

by volume of diacetyl to convert the normally gaseous paraflin hydrocarbon to unsaturated hydrocarbons.

3. A method of converting normally gaseous paraflln hydrocarbons to unsaturated hydrocarbons which comprises heating a normally gaseous paramn hydrocarbon to a temperature between about 930 F. and 1157 F.'in the presence of a relatively small amount of diacetyl.

4. A method of converting. normally gaseous paramn hydrocarbons to unsaturated hydrocarbons which comprises heating propane to a conversion temperature in the presence of a promoter comprising diacetyl.

5. A method of converting normally gaseous paraffin hydrocarbons to unsaturated hydrocarbons which comprises heating propane to a conversion temperature in the presence of about 1.0% or diacetyl by volume.

\ 930 F. to 1157f-F. in the presence lot 6. A method or converting normally gaseous paraflin hydrocarbons to unsaturated hydrocarbons which comprises heating propane to about about 1.0%

of diacetyl by volume.

-. '7. A method ofconverting higher molecular weight hydrocarbonsto lower molecular weight hydrocarbons which comprises heating hydrocarbons between about 930 F and 1157 F. in the presence of a relatively small amount of diacetyl.

8. A method of converting normally gaseous paraifin hydrocarbons to unsaturated hydrocarbons which comprises heating butane to a conversion temperature in the presence ofabout l%:.

of diacetyl by volume. v

9. A method of converting higher molecular weight hydrocarbons to lower molecular weight hydrocarbons which comprises heating hydrocarbons to a conversion temperature in the presence of a relatively small amount of diacetyl.

FRANCIS OWEN RICE. wms'ron, n. WALTERS. 

